CBSE Class 6 Science Body Movements Worksheet Set 04

Skeletal System

I. Fill in the blanks :

1. In Shark, skeleton is made up of _______________.

2. Snails move with the help of a _________________.

3. The _____________ in the earthworm helps to get a good grip on the ground.

4. __________________ joint allows movement in all directions.

5. Synovial cavity is found in _______________ joints.

6. Elbow joint is an example of ______________ joint.

II. Write True or False :

1. Muscles and bones are attached by means of ligaments. ___________

2. Mammals like tiger and elephant, use their hind limb and fore limb for locomotion. ___________

3. Snakes move in a straight line. ___________

4. When a muscle contracts, it get short and fatter. ___________

5. The finger bones do not have joints. ___________

III. Name the following :

1. Name the skull bone which are moveable.

2. Name the joint found in neck.

3. Name the shape of the body found in fish.

4. Name the joint present in between adjacent vertebrate in the backbone

I) Fill in the blanks :

1. The bones are moved by alternate _________________ and of __________________ of two sets of muscles.

2. Snails move with the help of muscular ____________

3. Fish swim by forming ___________________ alternately on two sides of the body.

4. The body and legs of cockroaches have hard coverings forming on outer _____________

5. Snakes ________________ on the ground by looping sideways.

II) Distinguish between the following :

1. Ball , socket joint and Hinge joint.

2. Bone and Cartilage.

III) Define

1. Skeleton

2. Ribcage

3. Joint

IV) Answer the following questions :

1. Name the different types of joints in our body.

2. Write the adaptation of a bird.

Q1. Fill in the blanks:

1. ___________, _____________ and _____________ form our skeleton.

2. The ____________ in earthworm helps to get a good grip on the ground.

3. Cockroaches have _________ pairs of legs and _________ pairs of wings.

4. Small bones that constitute the backbone are called________________.

5. X-ray shows the shapes of _____________ in our body.

6. Foot of snails is made up of ________________ only.

7. _____________ and ________________ are the body parts that can be rotated completely , as they have ________________________ joint.

8. Cartilage is found in ________________ and ___________________.

9. _________________________ is the part of the body we sit on.

10._______________________ joint allows movement in all direction and _____________ joint allows only back and forth movement.

11.Ribs join _____________ and ___________________ together to form ribcage.

12.An organism with outer skeleton is _________________.

13.The bones are moved by alternate _________________ and of __________________ of two sets of muscles.

14.Snails move with the help of muscular ____________________________________.

15. The body and legs of cockroaches have hard coverings forming on outer ______________.

Q2. Tick the correct option:

1. Total number of bones present in an adult human:
a) 202
b) 204
c) 206
d) 208

2. Which of these helps a fish to move / swim in water:
a) Fins
b) Streamlined Body
c) Tail
d) All of these

3. The joint present in elbow region:
a) Fixed Joint
b) Hinge Joint
c) Pivotal Joint
d) Ball and Socket Joint

4. The joint present in our neck region:
a) Fixed Joint
b) Hinge Joint
c) Pivotal Joint
d) Ball and Socket Joint

Q3. What is the significance of human skeleton?

Q4. Name the parts of the body protected by the following bones:
A. Skull
B. Rib Cage

Q5. List some properties of muscles?

Q6. How does earthworm fix its body parts to the ground?

Q7. List the features that help a bird to fly?

Q8. How do muscles work to move a bone? Explain.

Q9. What is a streamlined body and how is it useful to fish?

Q10. Why is the upper part of our ear not soft as the ear lobe?

Q11. Define:
A. Joints
B. Cartilage
C. Streamlined Body

Q12. Name the type of the joint present in the following parts of body:
a) Skull Bones
b) Shoulder Bones
c) Pelvic Girdle
d) Knee
e) Wrist
f) Lower Jaw-

Q13. Choose the correct answer :
1. ( Hinge joint / Pivot joint ) allows rotation.
2. Cockroach has ( 2 / 3 ) pair of legs.
3. In snails, a hard shell from the rigid ( endoskeleton / exoskeleton ).

Q14. Distinguish between the following :
1. Ball, socket joint and Hinge joint.
2. Bone and Cartilage.

Q15. During a field-trip some students visited an agricultural farm and saw a few birds eating earthworms. They enjoyed the scene and then they also started picking and killing the earthworms for pleasure. The farmer strongly objected and asked them to leave the field.
(a) What values do you find missing in the student's behaviour ?
(b) What makes an earthworm a “farmer’s friend”?

Q16. Shruti saw a road accident. She immediately helped the person and took him to the nearby hospital. The doctor took an X-Ray of the patient’s elbow.
(a) What is an X-Ray?
(b) Which joint is present in our elbows?
(c) What moral values are shown by Shruti?

Q1 Complete the following table

Q2 Define Joints.Name the varios types of movable joints

Q3 Bones are hard and cannot be bent?How do we bend our limbs at the elbow and knees?

Q4 What are fixed joints ?Give its example.

Q5 What is a ball and socket joint?Give its example.

Q6 How are we able to move our head up and down and sideways?

Q7 Name the joint that allows movement in one plane only?

Q8 Define pivotal joint.

Q9 What is the significance of human skeleton?(2 pionts)

Q10 What is a rib cage?

Q11 What are the important organs protacted by ribcage?

Q12 How many bones are present in our shoulder?

Q13 Differentiate between bone and cartilage?

Q15 What is the importance of cartilage?

Q16 What is the main function of a muscle and how does it work?

Q17 What will happen if cartilage is replaced by bone at our nose tip?

Q18 How does an earthworm moves?

Q19 Why do we say that earthworm are friends of farmers?

Q20 How does earthworm fix its body parts to the ground?

Q21 What area the special features that help a bird to fly?

Q22 What are the different body parts used by cockroach for its movements?

Q23 Explain the movement of snail?

Q24 What is the significance of streamlined body in fishes?

Q25 What is the importance of fins in fish?

Q26 Name the types of joints present in
a) Elbow
b) Shoulder
c) Wrist
d) Ankle
e) Knee
f) Skull
g) Neck
h) Lower jaw

Q28 Identify the types of joints involved in the following activities
a) Writing
b) Neck exercise
c) chewing
d) bowling
e) running

Q1 Complete the following table
Name of the animal Body parts How they move
Cockroach
Frog
Crow
Earthworm

Q2 Define Joints.Name the varios types of movable joints

Q3 Bones are hard and cannot be bent?How do we bend our limbs at the elbow and knees?

Q4 What are fixed joints ?Give its example.

Q5 What is a ball and socket joint?Give its example.

Q6 How are we able to move our head up and down and sideways?

Q7 Name the joint that allows movement in one plane only?

Q8 Define pivotal joint.

Q9 What is the significance of human skeleton?(2 pionts)

Q10 What is a rib cage?

Q11 What are the important organs protacted by ribcage?

Q12 How many bones are present in our shoulder?

Q13 Differentiate between bone and cartilage?

Q15 What is the importance of cartilage?

Q16 What is the main function of a muscle and how does it work?

Q17 What will happen if cartilage is replaced by bone at our nose tip?

Q18 How does an earthworm moves?

Q19 Why do we say that earthworm are friends of farmers?

Q20 How does earthworm fix its body parts to the ground?

Q21 What area the special features that help a bird to fly?

Q22 What are the different body parts used by cockroach for its movements?

Q23 Explain the movement of snail?

Q24 What is the significance of streamlined body in fishes?

Q25 What is the importance of fins in fish?

Q26 Name the types of joints present in
a) Elbow
b) Shoulder
c) Wrist
d) Ankle
e) Knee
f) Skull
g) Neck
h) Lower jaw

Q28 Identify the types of joints involved in the following activities
a) Writing
b) Neck exercise
c) chewing
d) bowling
e) running

<1M>

1.The joint between head and upper jaw is an example of:
(A) Hinge joint
(B) Pelvic joint
(C) Fixed joint
(D) Ball and socket joint

2.Name the joint where our neck joins the head.

3.In which direction does the hinge joint allow movements?

4.Name the joints which can not move.

5.Name the frame work which gives the shape to our body.

6.Which bones enclose the portion below the stomach in our bodys?

7.Name the structure which encloses and protects the brain.

8.The joints which move in all directions and the rounded end of one bone fits into the cavity of the other bone, are called:
(A) Ball and socket joints
(B) Pivotal joints
(C) Hinge joints
(D) Fixed joints

9.Ball and socket joints are present in:
(A) Joint between neck and head.
(B) Elbow joint
(C) Joint between shoulder and arm.
(D) Knee joint

10.joint moves the body part in forward, backward and in side ways direction.
(A) Hinge
(B) Pivotal
(C) Ball and socket
(D) Fixed

11.Match the following and choose the correct answer from the code given below:
Column I                            Column II
i) Neck                           A) moves back and forth.
ii) Arms                          B) do not move at all.
iii) Knee                         C) moves forward, backward and sideways.
iv) Bones in head          D) move in all direction
(A) i)-D); ii)-A); iii)-C); iv)-B
(B) i)-C); ii)-B); iii)-A); iv)-D)
(C) i)-B); ii)-D); iii)-C); iv)-A)
(D) i)-C); ii)-D); iii)-A); iv)-B)

12.The bone at the back which is made up of many small bones is called:
(A) Backbone
(B) Ribcage
(C) Pelvic bones
(D) Cartilage

13.The bones which enclose the portion of the body below the stomach:
(A) Backbone
(B) Hip bones
(C) Shoulder bones
(D) Rib cage

14.Which of the following statements are true:
i) Cartilage is found in upper parts of the ear.
ii) Ribcage joins the chest bone and backbone together.
iii) The bones in our body form a framework, called skeleton which gives shape to our body.
iv) Backbone is made up of only one long bone.
(A) i) and ii) only
(B) i), ii) and iv)
(C) i), ii) and iii)
(D) i), ii) and iv)

15.The animal that does not have any bones is:
(A) Earthworm
(B) Bird
(C) Elephant
(D) Fish

16.Earthworm secretes a slimy substance to help it in:
(A) Growth
(B) Movement
(C) Digestion
(D) Respiration

17.The outer skeleton of a snail is called :
(A) Shell
(B) Skull
(C) Backbone
(D) Both a & b

18.Cockroaches have ______pairs of legs and _____ pairs of wings.
(A) 2, 3
(B) 3, 3
(C) 3, 2
(D) 2, 2

19.The ____ musclesof a cockroach help in flying.
(A) Heart
(B) Breast
(C) Leg
(D) Flight

20.Movement in cockroaches is due to:
(A) Outer skeleton
(B) Legs
(C) Antennae
(D) Wings

21.The birds can fly because of:
(A) Forelimbs modified into wings.
(B) Hollow and light bones.
(C) Both a) & b)
(D) None of the above.

22.In birds, the bones of hind limbs are used in:
(A) Flying
(B) Respiration
(C) Walking and perching
(D) Prevention

23.The streamlinedbody in ___helps in movement.
(A) Snakes
(B) Fishes
(C) Earthworm
(D) Snail

24.The bony parts of the forelimbs in birds are modified as:
(A) Fins
(B) Hands
(C) Legs
(D) Wings

25.Which body part helps the fish to swim.
(A) Tail
(B) Fins
(C) Scales
(D) Forelimbs

26.Consider the following statements and choose the correct answer from the code given below.
i) Stream-lined is the shape in which body tapers at both ends.
ii) ball and socket joint can move in all direction.
iii) X-Ray shows the shape of the bones in our body.
iv) When muscles contract, they become shorter, stiffer and thicker.
(A) i) and iii) only
(B) i), ii) and iii)
(C) i), ii), and iv)
(D) All

27.Match the following and choose the correct answer from the code given below :
Column I                  Column II
i) Birds                   A) Slither
ii) Fishes                B) Fly and walk
iii) Snakes              C) Walk
iv) Humans            D) Swim
(A) i)-C); ii)-D); iii)-B); iv)-A
(B) i)-B); ii)-D); iii)-A); iv)-C)
(C) i)-B); ii)-A); iii)-C); iv)-D)
(D) i)-C); ii)-A); iii)-B); iv)-D)

28.Ancient Greek Philosopher, ________ in his book "Gait of animals" asked many questions to himself about the body movements in different animals.
(A) Aristotle
(B) Lavoiser
(C) Kennedy
(D) Newton

29.The body parts used by earthworms to get a good grip on the ground are:
(A) Thorns
(B) Bristles
(C) Slimy secretion
(D) Legs

30.When one muscle ____ ,the bone moves in that direction and other muscle____.
(A) contracts, relaxes
(B) relaxes, relaxes
(C) contracts, contracts
(D) relaxes, contracts

31.The ________ bones in birds are modified to hold the muscles for flight which are used to move the wings up and down.
(A) Shoulder
(B) Breast
(C) Forelimb
(D) Hind limb

32.Match the items of column 'A' with the items of column 'B':
Column A                         Column B
I Leg                         a. Friend of farmer
II Snail                      b. thigh bone
III Earthworm           c. swimming
IV Whale                  d. Covered with a hard shell.
(A) I - b, II - d, III - a, IV - c
(B) I - d, II - c, III - b, IV - a
(C) I - b, II - c, III - d, IV - a
(D) I - c, II - b, III - a, IV - d

33.Which one of the following animals has streamlined body?
(A) Earthworm.
(B) Snail.
(C) Fish.
(D) Snake.

34.Which of the following is not the function of the skeletal system?
(A) It forms the framework of body.
(B) It helps to protect the delicate organs.
(C) It helps in the movement of the body.
(D) It helps in digestion of food.

35.The movable skull bone is -
(A) Upper jaw.
(B) Lower jaw.
(C) Both (1) and (2).
(D) None of these.

36.Cockroach has _______ of jointed legs.
(A) Three pairs
(B) Two pairs
(C) Four pairs
(D) One pair

37.The joint which allows movement only in onedirection is-
(A) Pivotal joint.
(B) Ball and socket joint.
(C) Gliding joint.
(D) Hinge joint.

38.Snail moves with the help of-
(A) Contracting and expanding body.
(B) Muscular foot.
(C) Fins.
(D) None of these.

39.Movement of arm atthe elbow is due to ___.
(A) Ball and socket joint.
(B) Pivotal joint.
(C) Fixed joint.
(D) Hinge joint.

40.Which of the following statement is not true?
(A) The longest bone in our skeletal system is the thigh bone.
(B) The movement of a body as a whole is called locomotion.
(C) Cartilage is hard and bones are soft.
(D) Cockroaches have an external skeleton.

41.The systems which help in different types of movements in our body are__________.
(A) Skeletal and muscular system.
(B) Skeletal and circulatory system.
(C) Only the skeletal system.
(D) Muscular system and circulatory system.

42.The joint in the skull is a -
(A) Ball-socket joint.
(B) Gliding joint.
(C) Fixed joint.
(D) Hinge joint.

43.Find the odd one out -
(A) Eye.
(B) Mouth.
(C) Heart.
(D) Hand.

44.Total number of bones in our skeleton is -
(A) 406.
(B) 208.
(C) 206.
(D) 306

45.Which of the following is not an external organ in humans?
(A) Head.
(B) Hand.
(C) Leg.
(D) Lungs.

46.What meant by streamlined body shape?

47.Our skeleton is made up of -
(A) Bones.
(B) Cartilage.
(C) Both (1) and (2).
(D) None of these.

48.Joints of the bones help in the .... of the body.

49.A combination of bones and cartilages forms the of the body.

50.The bones at the elbow are joined by a joint.

51.The contraction of the pulls the bones during movement.

52.The muscle get bulged due to

53.What may happen if our body has no joints ?

54.What is the importance of skeleton in our body ?

55.What is the importance of rib cage in our body ?

<2M>

56.Name the organs used by : (a) fish during swimming (b) earthworms during moving.

57.What is a fixed joint? Give examples

58.What is cartilage where is it found?

59.What are called joints? Write any two uses .

60.write a short note on the gait of snail?

61.write about hinge joint?

62.Give one location for each of the following in our body.

(i) Hinge joint (ii) Pivotal Joint

63.Why does a snake move very fast and not in a straight line?

64.What is a ball and socket joint ?

65.Which of the skull bones are movable ?

66.Why can our elbow not move backwards ?

67.What are fixed joints ?

68.What is a pivotal joint ?

<3M>

69.What are joints? Name them.

70.What is a ball and socket joint?

71.What is cartilage? Where do we find it ?

72.What is a skeleton? Write its functions

73.write a short note on pivotal joint

74.What comprises the human skeleton?

75.Explain the movements in a cockroach

76.How do earth worms move? What two things help them in their movements? How

<5M>

77.How is a fish able to move easily in water?

78.How do bones move? Explain.

79.What makes the birds body suitable to fly

80.What is a ball and socket joint and Hinge joint ?Explain

81.Write a short note on pivotal joint and fixed joint

I) Fill in the blanks :

1. The bones are moved by alternate _________________ and of __________________ of two sets of muscles.

2. Snails move with the help of muscular ____________________________________.

3. Fish swim by forming ____________________________ alternately on two sides of the body.

4. The body and legs of cockroaches have hard coverings forming on outer __________________________________.

5. Snakes ___________________________ on the ground by looping sideways.

II) Distinguish between the following :

1. Ball , socket joint and Hinge joint.

2. Bone and Cartilage.

III) Define

1. Skeleton

2. Ribcage

3. Joint

IV) Answer the following questions :

1. Name the different types of joints in our body.

2. Write the adaptation of a bird.

Q1. Fill in the blanks:

1. ___________, _____________ and _____________ form our skeleton.

2. The ____________ in earthworm helps to get a good grip on the ground.

3. Cockroaches have _________ pairs of legs and _________ pairs of wings.

4. Small bones that constitute the backbone are called________________.

5. X-ray shows the shapes of _____________ in our body.

6. Foot of snails is made up of ________________ only.

7. _____________ and ________________ are the body parts that can be rotated completely , as they have ________________________ joint.

8. Cartilage is found in ________________ and ___________________.

9. _________________________ is the part of the body we sit on.

10._______________________ joint allows movement in all direction and _____________ joint allows only back and forth movement.

11.Ribs join _____________ and ___________________ together to form ribcage.

12.An organism with outer skeleton is _________________.

13.The bones are moved by alternate _________________ and of __________________ of two sets of muscles.

14.Snails move with the help of muscular ____________________________________.

15. The body and legs of cockroaches have hard coverings forming on outer ______________.

Q2. Tick the correct option:

1. Total number of bones present in an adult human:
a)202
b) 204
c) 206
d) 208

2. Which of these helps a fish to move / swim in water:
a) Fins
b) Streamlined Body
c) Tail
d) All of these

3. The joint present in elbow region:
a) Fixed Joint
b) Hinge Joint
c) Pivotal Joint
d) Ball and Socket Joint

4. The joint present in our neck region:
a) Fixed Joint
b) Hinge Joint
c) Pivotal Joint
d) Ball and Socket Joint

Q3. What is the significance of human skeleton?

Q4. Name the parts of the body protected by the following bones:
A. Skull
B. Rib Cage

Q5. List some properties of muscles?

Q6. How does earthworm fix its body parts to the ground?

Q7. List the features that help a bird to fly?

Q8. How do muscles work to move a bone? Explain.

Q9. What is a streamlined body and how is it useful to fish?

Q10. Why is the upper part of our ear not soft as the ear lobe?

Q11. Define:
A. Joints
B. Cartilage
C. Streamline
d Body

Q12. Name the type of the joint present in the following parts of body:
a) Skull Bones
b) Shoulder Bones
c) Pelvic Girdle
d) Knee
e) Wrist
f) Lower Jaw-

Q13. Choose the correct answer :
1. ( Hinge joint / Pivot joint ) allows rotation.
2. Cockroach has ( 2 / 3 ) pair of legs.
3. In snails, a hard shell from the rigid ( endoskeleton / exoskeleton ).

Q14. Distinguish between the following :
1. Ball , socket joint and Hinge joint.
2. Bone and Cartilage.

Q15. During a field-trip some students visited an agricultural farm and saw a few birds eating earthworms. They enjoyed the scene and then they also started picking and killing the earthworms for pleasure. The farmer strongly objected and asked them to leave the field.
(a) What values do you find missing in the student's behaviour ?
(b) What makes an earthworm a “farmer’s friend”?

Q16. Shruti saw a road accident. She immediately helped the person and took him to the nearby hospital. The doctor took an X-Ray of the patient’s elbow.
(a) What is an X-Ray?
(b) Which joint is present in our elbows?
(c) What moral values are shown by Shruti?

Q1 Answer the following in one word

a) A group of cells performing a special job____________

b) Strong ,bands that keep the bones together at joints_________

c) Tough bands which attach muscles to bones _____________

d) Animals that have backbones____________

Answer the following question

Q.2 Explain how you will make a ball and socket joint with the help of a paper strip and a rubber ball?

Q.3 How does an earthworm fix parts of its body to the ground?

Q.4 Choose the most appropriate answer from the options given below:

(i) The hinge joint allows movement in

a. all direction b. one plane only c. two planes only d. depends on where the joint is located in the body.

(ii) What acts as shock absorber at the joints?

a. ligaments b. cartilage c.tendons d. biceps

(iii) Which of these is not an organ system ?

a. heart b. respiratory . c. digestive d. excretory

Q.4 Write the significance of “ charkha” during independence movement

1. Fill in the blanks with suitable words:

Question 1.1. The place where two or more bones meet is called a-
Answer: joint
In simple words: Joints are the meeting points of bones in our body.

Exam Tip: Remember that joints allow different types of movements depending on their structure.

Question 1.2. ----- are not as hard as the bones and can be -----
Answer: Cartilages, bent
In simple words: Cartilage is a flexible and softer skeletal tissue found in areas like the ear and nose tip.

Exam Tip: Do not confuse cartilage with bone; cartilage can be bent easily without breaking.

Question 1.3. ----- are elastic tissues which work in pairs to move the bones.
Answer: Muscles
In simple words: Muscles pull on bones to cause movement by contracting and relaxing.

Exam Tip: Always state that muscles work in antagonistic pairs (when one contracts, the other relaxes).

Question 1.4. The 12 pairs of bones in the chest region are called-----
Answer: ribs (or rib cage)
In simple words: The rib cage protects vital organs like the heart and lungs.

Exam Tip: Note the exact number: 12 pairs of ribs.

Question 1.5. ----- gives us an idea about the shape and number of bones.
Answer: X-ray image
In simple words: X-rays allow doctors to view the internal skeletal structure clearly.

Exam Tip: X-rays are photographs of bone structures used for medical diagnosis.

2. Name the following:

Question 2.1. The joint that allows movement only in one plane -
Answer: Hinge joint
In simple words: Like a door hinge, this joint moves back and forth in one plane only (e.g., knee and elbow).

Exam Tip: Give examples like the elbow or knee when mentioning hinge joints.

Question 2.2. The type of joint in the hip and shoulder -
Answer: Ball and socket joint
In simple words: A rounded bone head fits into a cup-shaped cavity, allowing multi-directional movement.

Exam Tip: Ball and socket joints allow maximum movement in all directions.

Question 2.3. The system that protects the soft internal organs -
Answer: Skeletal system
In simple words: The skeleton acts as a hard protective armor for delicate organs.

Exam Tip: Link the skeletal system directly to protection and support.

Question 2.4. The animal that eats its way through the soil -
Answer: Earthworm
In simple words: Earthworms ingest soil to extract nutrients, loosening the earth in the process.

Exam Tip: Earthworms are known as farmers friends because they aerate the soil.

Question 2.5. The shape of the body of the bird that helps it to fly -
Answer: Streamlined shape
In simple words: A tapered body design reduces air resistance during flight.

Exam Tip: Both birds and fish possess a streamlined body to cut through air and water easily.

3. Multiple Choice Questions

Question 3.1. The joint that allows movement in all directions, is the
(a) Pivot joint
(b) Fixed joint
(c) Ball and Socket joint
(d) Hinge joint
Answer: (c) Ball and Socket joint
In simple words: The shoulder and hip permit circular and all-directional movement due to this joint type.

Exam Tip: Ball and socket = rotational and multi-directional movement.

Question 3.2. The elbow joint is a ----- joint.
(a) Ball and Socket joint
(b) Hinge joint
(c) Pivot joint
(d) Fixed joint
Answer: (b) Hinge joint
In simple words: The elbow can bend in only one direction like a door.

Question 3.3. The number of bones in our body are
(a) 200
(b) 204
(c) 206
(d) 208
Answer: (c) 206
In simple words: An adult human body consists of 206 separate bones.

Exam Tip: Remember that babies are born with more bones that fuse together over time.

Question 3.4. A streamlined body is found in
(a) Cockroach
(b) Snail
(c) Fish
(d) Earthworm
Answer: (c) fish
In simple words: Fish have tapered front and back ends to swim smoothly through water.

Exam Tip: Streamlined means pointed at both ends to reduce fluid friction.

Question 3.5. Which of the following animal is covered with a hard shell?
(a) Snail
(b) Earthworm
(c) Snake
(d) Cockroach
Answer: (a) Snail
In simple words: Snails carry a hard external shell (exoskeleton) for protection.

Exam Tip: The snail shell is a single continuous calcareous structure, not made of bones.

Question 3.6. Which of the following is made up of vertebrae?
(a) Cartilage
(b) Skull
(c) Backbone
(d) Bones of the leg
Answer: (c) Backbone
In simple words: The backbone consists of 33 small ring-like bones called vertebrae.

Exam Tip: The spinal column protects the delicate spinal cord.

Question 3.7. Earthworm moves with the help of
(a) Flagella
(b) Circular and longitudinal muscles
(c) Fins
(d) Hind limbs
Answer: (b) Circular and longitudinal muscles
In simple words: Earthworms alternately contract and relax their body muscles along with tiny bristles to crawl.

Exam Tip: Setae (tiny bristles) help earthworms grip the soil.

4. Answer the following with numbers:-

Question 4.1. No. of pairs of bones in the rib cage -
Answer: 12 pairs
In simple words: There are 12 pairs of ribs protecting the chest cavity.

Exam Tip: Total individual ribs equal 24.

Question 4.2. No. of bones in the backbone -
Answer: 33 vertebrae (in infants, fusing to 26 in adults)
In simple words: The spine is composed of stacked small bones called vertebrae.

Exam Tip: Standard textbook answer for Class 6 is 33 vertebrae.

Question 4.3. No. of pairs of muscles that help the bones to move -
Answer: Muscles work in pairs (one flexor and one extensor for each movement)
In simple words: Two muscles work together to pull a bone in opposite directions.

Exam Tip: Muscles can only pull, they cannot push.

Question 4.4. No. of bones in the skeleton system -
Answer: 206 bones
In simple words: An adult human skeleton has 206 bones.

Question 4.5. No. of pairs of wings in the body of a Cockroach attached to the breast -
Answer: 2 pairs
In simple words: Cockroaches have two pairs of wings attached to their breast region.

Exam Tip: Insects have distinct thoracic segments carrying legs and wings.

Question 4.6. No. of pairs of legs in the body of a cockroach -
Answer: 3 pairs (6 legs in total)
In simple words: All insects have three pairs of legs.

Question 5.1. Joint
Answer: A joint is the location where two or more bones connect to allow various types of movement or rigidity in the skeletal system.
In simple words: Joints are junctions where bones meet.

Exam Tip: Mention that some joints are movable while others are immovable (fixed).

Question 5.2. Cartilage
Answer: Cartilage is a smooth, elastic, and flexible type of supportive connective tissue found in joints, the tip of the nose, and outer ears that is softer than bone.
In simple words: Cartilage is flexible tissue that cushions joints and forms body parts like the ear lobe.

Exam Tip: Cartilage can bend without breaking.

Question 5.3. Bones
Answer: Bones are hard, rigid organs that compose the skeletal system, providing structural framework, support, protection for internal organs, and anchor points for muscles.
In simple words: Bones are hard structural parts of our body.

Exam Tip: Bones store minerals like calcium and phosphorus.

Question 5.4. Muscle
Answer: Muscles are soft, contractile tissue bundles composed of specialized cells that shorten and lengthen to produce force and facilitate body movements.
In simple words: Muscles pull bones to create movement.

Exam Tip: Muscles work by contraction and relaxation.

Question 5.5. Streamlined
Answer: A streamlined shape is tapered at both ends and wider in the middle, designed specifically to minimize fluid or air resistance during movement.
In simple words: A tapered body shape that helps animals move smoothly through water or air.

Exam Tip: Essential feature of birds and aquatic animals.

Question 5.6. Skeleton
Answer: The skeleton is the complete internal or external framework of bones and cartilage that gives shape, support, and protection to an organism's body.
In simple words: The structural framework of the body made of bones.

Exam Tip: Humans have an endoskeleton, whereas insects have an exoskeleton.

6. Fill in the blanks

Exam Tip: Learn joint locations and movements thoroughly as this is a high-yield table format question.

7. What are the structures associated with the movement of the following organisms?

Question 7.1. Cockroach
Answer: Three pairs of legs for walking and two pairs of wings attached to the breast for flying, supported by hard outer exoskeleton and muscles.
In simple words: Legs for walking, wings for flying, and body muscles.

Exam Tip: Cockroaches can walk, climb, and fly.

Question 7.2. Snail
Answer: Muscular foot and mucus secretion.
In simple words: A muscular foot helps snails glide forward.

Exam Tip: Snails leave a slimy trail of mucus to reduce friction.

Question 7.3. Earthworm
Answer: Circular and longitudinal muscles along with tiny hair-like bristles called setae.
In simple words: Muscles and tiny bristles help earthworms crawl.

Exam Tip: Mention circular and longitudinal muscles for full credit.

Question 7.4. Fish
Answer: Streamlined body, strong body muscles, and fins (pectoral, pelvic, caudal/tail fins).
In simple words: Fins and tail combined with a streamlined body and muscles help fish swim.

Question 7.5. Birds
Answer: Streamlined body, hollow light bones (pneumatic bones), modified forelimbs as wings, and strong flight muscles.
In simple words: Wings, powerful flight muscles, and light hollow bones.

Exam Tip: Hollow bones reduce body weight for flight.

Question 7.6. Snakes
Answer: Long backbone, numerous curves/loops in the body, muscles, and ventral scales/ribs.
In simple words: Slithering loops powered by backbone curves and scales.

Exam Tip: Snakes move in loops (serpentine motion) pushing against the ground.

8. Name the joints found in / between

Question 8.1. Fingers
Answer: Hinge joints
In simple words: Finger bones bend at hinge joints.

Exam Tip: Allows bending of fingers inward.

Question 8.2. Skull
Answer: Fixed joints (except the lower jaw)
In simple words: Bones of the cranium are fused tightly together.

Exam Tip: Remember the lower jaw is movable.

Question 8.3. Knee
Answer: Hinge joint
In simple words: Knees bend in one direction like hinges.

Exam Tip: Allows leg bending backwards.

Question 8.4. Shoulder
Answer: Ball and socket joint
In simple words: Allows complete circular arm rotations.

Exam Tip: Shoulder is a classic ball and socket joint.

Question 8.5. Neck
Answer: Pivot joint
In simple words: Allows the head to turn left, right, up, and down.

Exam Tip: Pivot joint connects skull to the first vertebra.

Question 8.6. Hip
Answer: Ball and socket joint
In simple words: Connects leg to the pelvic girdle allowing wide rotation.

Exam Tip: Similar in structure to the shoulder joint.

Question 8.7. Toes
Answer: Hinge joints
In simple words: Toes bend in a single plane like fingers.

Exam Tip: Similar to finger joint mechanisms.

9. Differentiate between:-

Question 9.1. Bones and Cartilages
Answer:
- Bones: Hard, rigid, non-flexible skeletal structures that support the body and protect internal organs.
- Cartilages: Softer, elastic, flexible connective tissues found in ear lobes, nose tips, and joint ends to cushion bones.
In simple words: Bones are hard and rigid, while cartilage is soft and bendable.

Exam Tip: Present differences in a point-wise format for maximum marks.

Question 9.2. Hinge joint and Ball and Socket Joint
Answer:
- Hinge Joint: Allows back-and-forth movement in only one plane (e.g., elbow, knee).
- Ball and Socket Joint: Allows movement in all directions / 360 degrees (e.g., shoulder, hip).
In simple words: Hinge joints move like a door in one direction, while ball and socket joints rotate freely in all directions.

Exam Tip: Always include examples for each joint type.

10. State whether the following are True or False. If false correct the statement:

Question 10.1. The skeletal system consists of bones and cartilages -
Answer: True.
In simple words: Both bones and cartilage make up our skeleton.

Exam Tip: Statement is factually correct.

Question 10.2. Our skull is made up of movable joints -
Answer: False.
Corrected statement: Our skull is made up of fixed (immovable) joints, except for the lower jaw.
In simple words: Skull bones are tightly fused together and cannot move.

Question 10.3. Cartilages are harder than bones -
Answer: False.
Corrected statement: Bones are harder than cartilages.
In simple words: Cartilage is softer and more flexible than bone.

Exam Tip: Cartilage can be bent, but bones cannot.

Question 10.4. Joints are not present in our finger bones -
Answer: False.
Corrected statement: Joints (hinge joints) are present in our finger bones.
In simple words: Finger bones have joints that allow them to bend.

Exam Tip: Without joints, fingers would remain rigid.

Question 10.5. Cockroaches have an outer skeleton -
Answer: True.
In simple words: Insects possess an exoskeleton on the outside of their body.

Exam Tip: Exoskeleton provides both support and external protection.

11. Answer the following briefly:-

Question 11.1. What are the main functions of the Skeletal System?
Answer: 1. Provides a rigid structural framework and shape to the body.
2. Protects delicate internal organs (e.g., skull protects brain, rib cage protects heart and lungs).
3. Anchors muscles to facilitate movement.
4. Produces blood cells in the bone marrow.
In simple words: The skeleton supports the body, protects organs, and helps in movement.

Exam Tip: List at least 3 clear points for full marks.

Question 11.2. What is a Ball and Socket joint?
Answer: A ball and socket joint is a movable joint where the rounded head (ball) of one bone fits into the hollow, cup-shaped cavity (socket) of another bone, allowing multi-directional movement and rotation.
In simple words: A rounded bone fitting into a cup-like socket allowing rotation in all directions.

Exam Tip: Mention shoulder and hip as examples.

Question 11.3. What is the function of the Pivotal joint?
Answer: A pivotal joint allows rotational movement, enabling the head to turn side to side and bend forward, backward, or sideways (e.g., the joint where the neck joins the head).
In simple words: It lets the neck turn side-to-side and up-and-down.

Exam Tip: Connect pivot joint directly to neck rotation.

Question 11.4. What is a Skeleton? What is it comprised of?
Answer: The skeleton is the internal (or external) framework of the body that gives shape and support. It is comprised of all the bones, cartilage, and joints in the body.
In simple words: The framework of bones and cartilage supporting the body.

Exam Tip: Include bones and cartilage in your definition.

Question 11.5. What is a joint? Give an example.
Answer: A joint is the point or junction where two or more bones meet in the body. Example: Knee joint or elbow joint.
In simple words: Meeting point of bones, e.g., knee.

Question 11.6. What is a Rib cage? What is its function?
Answer: The rib cage is a bony cage formed by 12 pairs of curved ribs connected to the backbone and chest bone (sternum). Its primary function is to protect vital internal organs such as the heart and lungs.
In simple words: The 12 pairs of chest bones that protect the heart and lungs.

Exam Tip: Mention protection of heart and lungs.

Question 11.7. What is a backbone? How many bones does it comprise of?
Answer: The backbone (spine or vertebral column) is a strong flexible column running from the neck down to the lower back that supports the body and encloses the spinal cord. It comprises 33 small ring-like bones called vertebrae.
In simple words: The spinal column made of 33 vertebrae running down the back.

Exam Tip: State both the term 'vertebrae' and the count '33'.

Question 11.8. What are Muscles?
Answer: Muscles are bundles of soft, elastic, contractile tissues attached to bones that work in pairs by contracting and relaxing to pull bones and produce body movement.
In simple words: Elastic tissues that pull on bones to make them move.

Exam Tip: Note that muscles can only pull; they cannot push.

Question 11.9. How is earthworm useful to the plants?
Answer: Earthworms ingest soil and organic matter, aerating the soil as they burrow. Their waste (vermicompost) adds rich nutrients to the soil, which helps plants grow better. Thus, they are called farmer's friends.
In simple words: Earthworms loosen soil and enrich it with nutrients, helping plants grow.

Exam Tip: Mention soil aeration and nutrient enrichment.

12. Explain in detail :-

Question 12.1. Describe the features in the body of a fish that helps it to swim.
Answer: 1. Streamlined Body: The head and tail are tapered, allowing the fish to cut through water smoothly with minimum resistance.
2. Fins: Pectoral and pelvic fins help in balancing and steering, while the caudal (tail) fin acts as a rudder to change direction.
3. Flexible Backbone and Muscles: Strong muscles make the body curve from side to side rapidly, creating pushes against water to propel the fish forward.
In simple words: Streamlined shape, fins, and strong muscles help fish swim easily.

Exam Tip: Cover streamlined shape, fins, and muscular tail action.

Question 12.2. The body of a bird is suited for flying. Justify
Answer: 1. Hollow Bones: Bird bones are hollow and light (pneumatic bones), reducing body weight for flight.
2. Modified Forelimbs: Forelimbs are modified into wings that provide lift and thrust.
3. Streamlined Body: Reduces air resistance during flight.
4. Strong Flight Muscles: Chest muscles (pectoralis) flap the wings powerfully.
In simple words: Hollow bones, wings, streamlined bodies, and strong muscles make flight possible.

Exam Tip: Highlight hollow bones and wings as key adaptation features.

Question 12.3. Describe the four main types of joints with suitable examples.
Answer: 1. Ball and Socket Joint: Allows movement in all directions (360 degrees). Example: Shoulder and hip joints.
2. Hinge Joint: Allows back-and-forth movement in one plane like a door hinge. Example: Elbow and knee joints.
3. Pivot Joint: Allows rotational movement (side-to-side and up-and-down). Example: Neck joint.
4. Fixed (Immovable) Joint: Does not allow any movement as bones are tightly interlocked. Example: Bones of the skull.
In simple words: The four joint types are ball and socket (all directions), hinge (one direction), pivot (rotation), and fixed (no movement).